Ethylene, higher alpha-olefin comonomer and dienes, especially vinyl norbornene and polymers made using such processes

ABSTRACT

This invention relates to olefin polymerization processes for polymerizing ethylene, higher alpha-olefin comonomer and dienes, especially vinyl norbornene, and especially process for producing amorphous or semi-crystalline polymers such as EPDM. The invention also relates to the novel polymers produced by such processes. The invention furthermore relates to articles of manufacture with an improved balance of toughness and curing properties.

This application is the National Stage of International Application No.PCT/US03/19449, filed Jun. 18, 2003, which claims the benefit of U.S.Provisional Application No. 60/389,980, filed Jun. 19, 2002, the entiredisclosures of which are hereby incorporated herein by reference.

FIELD

This invention relates to olefin polymerization processes forpolymerizing ethylene, higher alpha-olefin comonomer and dienes,especially vinyl norbornene, and especially processes for producingamorphous or semi-crystalline polymers such as EPDM. The invention alsorelates to the novel polymers produced by such processes. The inventionfurthermore relates to articles of manufacture with an improved balanceof toughness and curing properties.

BACKGROUND

EPDM's containing vinyl norbornene (VNB), which is a non-conjugateddiene having two polymerizable double bonds, are known from EP843698;EP843702 and EP843701. These polymers have long chain branching (LCB).High levels of LCB improve processability, but may impair physicalproperties (tear) of final product after conversion of the polymer byextrusion or molding etc. The two double bonds are both capable ofpolymerization with olefins in the presence of transition metalcatalysts.

The prior art describes the benefit of VNB over ethylidene norbornene(ENB). ENB is a non-conjugated diene having one double bond that iscopolymerizable using a transition metal catalyst. The other double bondis not so polymerizable and remains available in the final polymer forsubsequent reaction, e.g., sulfur curing. The VNB derived EPDM providesimproved cure rate and performance in free-radical curing, improvedprocessability from the highly branched structure and requires a lowlevel of diene to provide suitable physical properties in the finalproduct comparable to ENB derived EPDM.

WO99/00434 describes combining ENB, VNB and specific branchinginhibitors to produce EPDM with reduced branching. The ENB derived unitsare present in amounts well in excess of the amount of VNB. The spectrumof LCB and MWD variations that can be obtained appear to be limited bythe process characteristics (a branching modifier is used). Very lowlevels of branching may be hard to obtain because of cationic branchinggenerated by the ENB. Broad molecular weight distribution is favored.

In the present invention, an alternative method is used for controllingLCB, which permits greater reliance on the non-conjugated diene typewhich has two polymerizable double bonds, such as VNB. In thisalternative method no, or much less, ENB can be used. Thus the benefitsdescribed for prior art EPDM polymers derived predominantly from VNB asthe diene can be obtained, with the added benefit of balancing theinfluence of LCB on processing and the properties of the final product.

This method relies not on chemical branching modifiers, but on thepredominant addition of the VNB (or equivalent diene having twopolymerizable double bonds) in a second polymerization reaction stepunder polymerization conditions which allow for controlled incorporationof the VNB.

It is known to make EPDM type polyolefins, generally those having ENBderived units, in a continuous stirred tank series reactor layout,primarily to obtain broader molecular weight distributions and theattendant processability benefits resulting therefrom. Reference is madeto U.S. Pat. No. 4,306,041; EP227206 and WO99/45047; WO99/45062discusses polymer dispersions. The production of an EPDM productcontaining predominantly units of VNB for the diene so as to controllevels of LCB is not described.

U.S. Pat. No. 6,319,998 and WO 99/45062 describe processes usingmetallocene type catalysts that have high activity and extremelyefficient incorporation of diene. This leads to high levels of LCB, andin some cases the formation of gel. The process described herein employsa catalyst capable of controlling VNB incorporation so as to limit LCBformation.

For additional background see: WO 99/00434, U.S. Pat. No. 6,207,756, WO98/02471, U.S. Pat. Nos. 3,674,754, 4,510,303 3,629,212, 4,016,342,5,674,613, EP 1088855, U.S. Pat. No. 6,281,316, EP 784062, U.S. Pat.Nos. 4,510,303, 5,698,651 and 6,225,426.

SUMMARY

The present invention relates to a process for solution polymerizingethylene, higher alpha-olefin and diene having two polymerizable doublebonds which comprises: A) reacting in a first step ethylene, higheralpha-olefin comonomer and optionally one or more dienes to produce apolymer composition comprising from 0 to less than 1 mol % of dienehaving one or two polymerizable double bonds, in the presence of acatalyst system;

reacting in a second step ethylene, higher alpha-olefin comonomer andone or more dienes at least one of which is a diene having twopolymerizable double bonds in the presence of a catalyst system, theamount of diene having two polymerizable double bonds being added to thereactor in the second step being more than 50% of the total diene addedin the first and second step combined; and C) recovering a polymerproduct having from 0.02 to 2 mol % of units derived from the dienehaving two polymerizable double bonds, and a branching index of greaterthan 0.5.

In one embodiment, the present invention relates to a process forsolution polymerizing ethylene, propylene and diene having twopolymerizable double bonds which comprises: A) reacting in a first stepethylene, propylene and optionally one or more dienes to produce apolymer composition comprising from 0 to less than 1 mol % of dienehaving one or two polymerizable double bonds, in the presence of avanadium based catalyst system; B) reacting in a second step ethylene,higher alpha-olefin comonomer and diene comprising vinyl norbornene inthe presence of the same catalyst system, the amount of vinyl norborneneadded in the second step being more than 50% of the total diene added inthe first and second step combined; and C) recovering a polymer producthaving from 0.1 to 1 mol % of units derived from vinyl norbornene and atotal of no more than 5 mol % diene derived units, from 50 mol % to 90mol % ethylene derived units and a balance of propylene derived units; abranching index of greater than 0.5, preferably greater than 0.7 and aMooney viscosity of from 15ML to 100 MST.

This invention further relates to a polymer product which comprises incombination: a) from 50 to 90 mol % of ethylene derived units; b) from0.1 to 2 mol % of VNB derived units; c) an optional amount of ENBderived units; d) a balance of higher alpha olefin derived units; and e)a branching index of greater than 0.5.

More specifically this invention relates to a polymer product whichcomprises in combination: a) from 50 to 90 mol % of ethylene derivedunits; b) from 0.1 to 1 mol % of VNB derived units; c) an optionalamount of ENB derived units; d) a balance of propylene derived units; e)a branching index of greater than 0.5, preferably greater than 0.7; andf) a Mooney viscosity of from 15ML to 100 MST. Articles made from suchpolymers are also described.

DETAILED DESCRIPTION

The polymer compositions of this invention comprise units derived fromethylene, alpha-olefin and diene having two polymerizable double bonds.Such “EPDM-type” polymers are well known in the art. The alpha olefin ispreferably one or more C₃ to C₈ alpha olefins, more preferably propyleneor butene, most preferably propylene.

The diene having two polymerizable double bonds is preferably selectedfrom the group consisting of: 1,4-hexadiene, 1,6 octadiene,5-methyl-1,4-hexadiene, 3,7-dimethyl-1,6-octadiene, dicyclopentadiene(DCPD), norbornadiene, 5-vinyl-2-norbornene (VNB), and combinationsthereof, most preferably VNB. The amount of diene having twopolymerizable double bonds in the polymer product may vary from 0.2 to 2mol %, preferably from 0.1 to 1 mol %, more preferably from 0.1 to 0.5mol %. Other dienes may be added during the polymerization process. Allranges disclosed herein are inclusive unless otherwise noted.

In a preferred embodiment, the maximum amount of ethylene derived unitsis 90 mol %, preferably from 50 to 90 mol %. Ethylene content isdetermined by FTIR, ASTM D3900, and is not corrected for diene content.ENB or VNB content incorporated in the polymer is determined by FTIR,ASTM D6047. Other dienes can be measured via 1H NMR. These methods onlymeasure available unsaturation. Thus the measured incorporation may belower than the actual incorporation because dienes having pendantunsaturated moities have been converted, e.g., by hydrogen, are notdetected in the measurement. When both ENB and VNB are present, ¹³C NMRshould be used to determine diene content

The polymers of this invention preferably have a Mooney viscosity of15ML to 100MST, more preferably from 20ML to 80MST determined asdescribed below.

As used herein Mooney viscosity is measured as ML (1+4) at 125° C. inMooney units according to ASTM D-1646. However, Mooney viscosity valuesgreater than about 100 cannot generally be measured under theseconditions. In this event, a higher temperature can be used (i.e. 150°C.), with eventual longer shearing time (i.e. 1+8 @ 125 or 150° C.), butmore preferably, the Mooney measurement is carried out using anon-standard small rotor as described below.

The non-standard rotor design is employed with a change in Mooney scalethat allows the same instrumentation on the Mooney machine to be usedwith higher Mooney polymers. This rotor is termed MST—Mooney Small Thin.One MST point is approximately 5 ML points when MST is measured at (5+4@200 C) and ML is measured at (1+4 @ 125° C.).

ASTM D1646—99 prescribes the dimensions of the rotor to be used withinthe cavity of the Mooney machine. This prescription allows a large and asmall rotor differing only in diameter. These are referred to as ML(Mooney Large) and MS (Mooney Small). However, EPDM can be produced atsuch high MW that the torque limit of the Mooney machine can be exceededusing these standard prescribed rotors. In these instances, the test isrun using the MST rotor that is both smaller in diameter and thinner.Typically when the MST rotor is employed, the test is also run atdifferent time and temperature. The pre-heat time is changed from thestandard 1 minute to 5 minutes and the test is run at 200 C instead ofthe standard 125 C. Thus, the value will be reported as MST (5+4), 200C. Note that the run time of 4 minutes at the end of which the Mooneyreading is taken remains the same as the standard conditions. For thepurposes of an approximate conversion between the two scales ofmeasurement, multiply the MST (5+4) 200 C Mooney value by 5 to obtainthe ML(1+4) 125 C equivalent. The MST rotor should be prepared asfollows:

The rotor should have a diameter of 30.48+/−0.03 mm and a thickness of2.8+/−0.03 mm (tops of serrations) and a shaft of 11 mm or less indiameter.

The rotor should have a serrated face and edge, with square grooves of0.8 mm width and depth of 0.25–0.38 mm cut on 1.6 mm centers. Theserrations will consist of two sets of grooves at right angles to eachother (form a square crosshatch).

The rotor is positioned in the center of the die cavity such that thecenterline of the rotor disk coincides with the centerline of the diecavity to within a tolerance of +/−0.25 mm. A spacer or a shim may beused to raise the shaft to the midpoint.

The wear point (cone shaped protuberance located at the center of thetop face of the rotor) shall be machined off flat with the face of therotor.

For blends of polymers, the Mooney viscosity is obtained using therelationship shown in Equation 1 below.Log ML=n _(A) log ML _(A) +n _(B) log ML _(B)  (Equation 1)

Where all logarithms are to the base 10.

ML is the Mooney viscosity of a blend of two polymers A and B eachhaving individual Mooney viscosities ML_(A) and ML_(B), respectively.The fraction of polymer A in the blend is n_(A), while the fraction ofthe polymer B is n_(B). In the present application, Equation (1) hasbeen used to generate blends of high Mooney polymer (A) with a lowMooney polymer (B) that have measurable Mooney viscosities under (1+4 @125° C.) conditions. Knowing ML, ML_(A) and n_(A), ML_(B) can be easilycalculated.

For high Mooney polymers, ML_(A) is conveniently measured using the MSTrotor as described above. In this work, we have found the followingcorrelation: ML (1+4 @ 125° C.)=5.13*MST (5+4 @ 200° C.).

The polymers of this invention are not highly branched, therefore, thebranching index is at least 0.5, more preferably at least 0.7, even morepreferably at least 0.9,

The relative degree of branching in ethylene, alpha-olefin, dienemonomer elastomeric polymers is determined using a branching indexfactor (BI). Calculating this factor requires a series of threelaboratory measurements of polymer properties in solutions as disclosedin VerStrate, Gary, “Ethylene-Propylene Elastomers”, Encyclopedia ofPolymer science and Engineering, 6, 2^(nd) edition (1986). These are:

M_(w, GPC LALLS), weight average molecular weight measured using a lowangle laser light scattering (LALLS) technique in combination with GelPermeation Chromatography (GPC) (ii) weight average molecular weight(M_(w, DRI)) and viscosity average molecular weight (M_(v, DRI)) using adifferential refractive index (DRI) detector in combination with GPC and(iii) intrinsic viscosity (IV) measured in decalin at 135° C. The firsttwo measurements (i and ii) are obtained in a GPC using a filtereddilute solution of the polymer in trichlorobenzene.

An average branching index (i.e., branching index as used herein) isdefined as:

${BI} = \frac{M_{v,{br}} \times M_{w,{DRI}}}{M_{w,{{GPC}\mspace{14mu}{LALLS}}} \times M_{v\mspace{14mu}{GPC}\mspace{14mu}{DRI}}}$where, M_(v,br)=(IV/k)^(1/a); and ‘a’ is the Mark-Houwink constant(=0.759 for ethylene, propylene diene elastomeric polymers in decalin at135° C.). From equation (1) it follows that the branching index for alinear polymer is 1.0. For branched polymers, the extent of branching isdefined relative to the linear polymer. Since at a constant numberaverage molecular weight M_(n), (M_(W))_(branch)>(M_(W))_(linear), BIfor branched polymers is less than 1.0, and a smaller BI value denotes ahigher level of branching. In place of measuring IV in decalin, it isalso acceptable to measure IV using a viscosity detector in tandem withDRI and LALLS detectors in the so-called GPC-3D instrument. In thiscase, ‘k’ and ‘a’ values appropriate for the GPC solvent should be usedin the equation above.

Any number and type of additives may be compounded with the polymercompositions of this invention including but not limited to: carbonblack, plasticizer like paraffinic oil, process aids such as fattyacids, waxes etc., antioxidants, curatives, fillers such as calciumcarbonate, clay, silica and the like, antiozonants, tackifiers, andscorch inhibiting agents.

These polymer compositions may be cured or vulcanized according to knownmethods, for example using agents such as peroxide that forms a C—C bondor hydrosilation that forms a C—Si—C bond as is described in“Vulcanization”, Chapter 7 of “Science and Technology of Rubber”, by A.Y. Coran, (F. R Eirich editor) Academic Press Inc., 1978.

Generally speaking, any process may be used to prepare the polymers ofthis invention including single and parallel reactors or by mechanicalblending. The preferred process, though, is that of this invention whichemploys the use of two steps, preferably in series reactors, asdescribed below.

Process control and efficiency is best achieved when operating in aseries reactor arrangement in which the solution resulting from thefirst step is supplied as the feed stream, with optional added monomer,to the second step. Preferably the process steps are performed withsufficient back mixing so as to eliminate concentration gradients in thebulk of the reactors and ensure random polymerization by using at leasttwo continuous stirred tank reactors.

The contribution from the first reactor step is preferably major.Advantageously the first step in the upstream reactor produces at least80 wt % and/or less than 95 wt % of the total polymer, preferably atleast 90 wt %.

Low levels of LCB in the final product can be obtained by controllingthe participation of the pendent double bond during polymerization.Preferably the diene supplied to the first step is less than half thatsupplied in the second step so as to reduce LCB formation.

By minimizing the participation of the diene having two copolymerizabledouble bonds in the first step and by reducing or eliminating theparticipation of the pendent double bond of the diene in thepolymerization during the second step, low or very low levels of LCBformation can be created. LCB formation can be minimized via choice ofcatalyst system, reactor temperature, catalyst rates and the like.

The catalyst system (i.e., active catalyst or catalyst plus activatorwith or without support) may be any catalyst system capable of producingthe target polymer product in a two (or more) step reaction process. Wehave found that vanadium based catalyst systems as opposed tometallocene based catalyst systems tend to be capable of doing this. Inour experience, the commonly known and used metallocene type catalystsystems are too active and too efficient at incorporating the VNBpendant vinyl group. This leads to LCB and gel formation rather than tothe product of the present invention. We do, however, contemplate thatselected metallocenes might behave more like vanadium based catalystsystems and prove useful in the process of this invention.

Preferably a vanadium based catalyst system is selected from vanadiumtetra chloride/aluminum sesquichloride (co-catalyst) type andvanadiumoxytrichloride/aluminum sesquichloride catalyst systems so as toprovide an improved propensity for incorporating higher alpha olefins.

Given the ability to produce very low levels of LCB by using one or moreof the measures indicated previously, it may be desirable to producepolymers having properties intermediate those having very low levels ofLCB and the highly branched products made with, for example VNB, untilnow. For such purposes a copolymerizable, diene containing twopolymerizable double bonds may be added in the first step but in anamount of less than 50% of the total added of the diene containing twopolymerizable double bonds. It may also be desired without departingfrom the inventive concept to add a copolymerizable, diene containingonly one polymerizable double bond, in the first step to increase sulfurcurable unsaturation along the polymer chain.

The overall monomer composition of the polymer can range broadly.Preferably the polymer contains 50 to 90 mol % of ethylene derivedunits, more preferably from 50 to 80 mol % ethylene derived units, from0.1 to 5 mol % of one or more diene derived units as determined byFT-IR/HNMR wherein the higher alpha olefin forms the balance and hasfrom 3 to 8 carbon atoms and comprises preferably propylene. In apreferred form the polymer contains at least 50 mol % of the total dieneof VNB derived units, preferably from 0.1 to 1 mol % of the totalpolymer, more preferably from 0.1 to 0.5 mol %, which VNB derived unitshave a pendant double bond available for cross-linking. The polymer mayhave overall a Mooney of from 15 ML to 100 MST, in the absence of Mooneylowering extender oils. Molecular weight can be controlledconventionally including the option of adding hydrogen.

ENB may be added during polymerization, preferably to the first reactorin order to obtain a sulfur curable polymer. Generally, to impart sulfurcurability, from 0.5 to 10 mol % ENB is preferably added.

Because of the differential monomer addition CD may be broadened to agreat degree. Preferably the polymer has an Mw/Mn<6 and/or an Mz/Mw<5.

Specifically, EPDM with VNB as a diene is generally prepared in a singleContinuous Flow Stirred Tank Reactor (CFSTR) in a temperature range of20–65° C., a pressure of 50–200 PSI (350–1400 kPa) and residence time of5–15 minutes.

Branching may be reduced to a controlled extent by differential feedingof the VNB so as to minimise the participation of pendent double bond.

The emphasis in the first step should be to produce either a copolymeror a terpolymer with just enough diene to provide the desired overallcure characteristics so LCB can be minimized. The emphasis in the secondstep should be on the introduction of the majority of VNB into thepolymer chains with reduced LCB formation compared to the first step.The absolute level of VNB can be selected to obtain the desired curingproperties. More VNB provides better curability.

According to embodiments of this invention, a range of LCB levels andcure properties can be provided through the use series reactoroperation, in which the VNB is fed only or mainly to the second reactor.If the catalyst is fed only to the first reactor, very low catalystconcentration remains in the second reactor to produce a small fractionof the total polymer. Because this fraction produced in the second stepcan be kept small, ultra low propylene conversion can be targetedwithout undermining the polymerization efficiency appreciably while VNBis being incorporated. It is believed that the VNB incorporated in thesecond step undergoes minimal reaction of the pendent double bond,permitting formation of an overall linear polymer. The slight broadeningof molecular weight distribution resulting from multi-steppolymerization may enhance the processability of such a substantiallylinear polymer.

As used herein, molecular weight distribution Mw/Mn is determinedaccording to well known methods, for example by GPC (Gel PermeationChromatography) on a Waters 150 gel permeation chromatograph equippedwith a differential refractive index (DRI) detector and a ChromatixKMX-6 on line light scattering photometer. The system is used at 135° C.with 1,2,4-trichlorobenzene as the mobile phase using Shodex (ShowaDenko America, Inc) polystyrene gel columns 802, 803, 804 and 805. Thistechnique is discussed in “Liquid Chromatography of Polymers and RelatedMaterials III”, J. Cazes editor, Marcel Dekker. 1981, p. 207, which isincorporated herein by reference. No corrections for column spreadingare employed; however, data on generally accepted standards, e.g.National Bureau of Standards Polyethylene 1484 and anionically producedhydrogenated polyisoprenes (an alternating ethylene-propylenecopolymers) demonstrate that such corrections on Mw/Mn (=MWD) are lessthan 0.05 units. Mw/Mn is calculated from elution times. The numericalanalyses are performed using the commercially available Beckman/CIScustomized LALLS software in conjunction with the standard GelPermeation package. Calculations involved in the characterization ofpolymers by ¹³CNMR follow the work of F. A. Bovey in “PolymerConformation and Configuration” Academic Press, New York, 1969.Reference to Mw/Mn implies that the Mw is the value reported using theLALLS detector and Mn is the value reported using the DRI detectordescribed above.

EXAMPLES

The two steps of the inventive process were accomplished by carrying outthe polymerization in a series arrangement of two Continuous FlowStirred Tank Reactors with hexane as the solvent. Vanadium tetrachloride was used as the catalyst and ethyl aluminum sesquichloride asthe cocatalyst. The catalyst and co-catalyst were added only in thefirst step in a molar ratio of 5 to 1. The carryover of live catalystspecies to the second tank provided the desired environment for thesecond step. The first step was carried out at 30° C. The temperature inthe second step was dependent on the relative amount of polymer made inthat step but, generally ranged from 34 to 37° C. The polysplit in termsof the proportion by weight of polymer made in the first step versusthat made in the second step was in the range 87–95. The catalyst ratewas adjusted to produce about 480–895 gm of polymer per gram ofcatalyst. The residence time in the reactor was maintained at 8.5minutes. The polymer concentration in the solvent was between 2.5% and2.8%. Propylene was fed only to the first step with carryover ofunreacted portion providing the feed to the second step.

High VNB conversion (in terms of VNB units incorporated into the polymerbackbone with the second double bond intact) is obtained coincident withlow propylene conversion (in terms of propylene units incorporated intothe polymer backbone). This data suggests that the propensity toincorporate the double bond in the alpha olefin is about the same as thependent double bond on VNB. Therefore, a reaction environment that wouldbe poor for the incorporation of alpha olefin in the backbone of thepolymer chain would also discourage the participation of the pendentdouble bond in polymerization and therefore produce a polymer with lowlevels of LCB formed by polymerization of the second double bond of VNB.Where it is the objective to maximize the contribution of VNB towardssubsequent curing and where it is intended to minimize the contributiontowards LCB formation, such as for example when VNB is added in a secondreaction step, low propylene conversion is targeted.

Ethylene was fed to both steps separately. VNB was fed only to thesecond step. The conversion of ethylene in the first step was close to100%. The overall ethylene utilization in the process was 79–97%. Theconversion of propylene in the first step was 70–80%. The overallutilization of propylene was 72–93% as residual propylene isincorporated in the second step. The overall conversion of VNB based onavailable VNB in the polymer was from 8–21%.

-   Example 1 is for comparative purposes and was made without any VNB    feed in both steps;-   Example 2 was made with the addition of 2 Kg/hr VNB to the second    step;-   Example 3 was made with the addition of 6 Kg/hr VNB to the second    step;-   Example 4 was made with the addition of 7 Kg/hr VNB to the second    step;-   Example 5 was similar to Example 4 with additional catalyst feed in    step 1; and-   Example 6 is a comparative example made according to prior art in a    single step process.

TABLE 1 Example 1 Example 6 (not (not according to Example according toinvention) 2 Example 3 Example 4 Example 5 invention) ML (1 + 4) 57 62.365 79.2 41 85.8 125 C MLR 208 245.7 269 552 265.2 1659 Wt % C2 62.2 61.561.6 61.2 59.0 60.2 Wt % VNB 0 0.42 0.85 0.92 0.8 1 Wt % C3 37.8 38.338.1 38.4 40.7 39.4 Polysplit 87 93 92 89 91 Single (%) Reactor Mw, 1.952.10 2.38 2.09 2.26 8.62 Lalls/Mn, DRI (Mz/Mw), 1.50 1.64 2.14 1.72 1.913.85 Lalls Branching 0.95 0.91 0.83 0.89 0.83 0.41 Index

The molecular weight distribution remains relatively narrow; the levelof LCB is low as is evident from the high branching index of theExamples according to the invention which can approximate that ofExample 1 which contains no VNB derived units.

The polymers were evaluated in a plasticizer-free black-filledformulation and vulcanized using a peroxide curative. The formulation isshown in Table 2 and the cure and physical property data in Table 3.

TABLE 2 Ingredient Function Amount in parts by wt of total PolymerStructural strength 100 N 550 Processing Oil 50 Agerite Resin D 1Structol W34 2 Dicup 40 KE 6 SR 350 (TMPTMA) Anti-oxidant 2

TABLE 3 Example Example ODR @ 1 (not 6 (not 180 C. according according(320 F.), 3 to Example Example Example Example to deg arc invention) 2 34 5 invention) ML dNm 29.0 31.4 30.0 33.7 15.9 36.1 MH dNm 124.8 135.4137.9 144.2 110.6 159.7 ts2 min 0.6 0.6 0.5 0.6 0.6 0.6 t50 min 1.5 1.61.5 1.5 1.7 1.7 t90 min 3.3 3.4 3.4 3.5 4.0 3.6 t98 min 5.1 5.1 5.3 5.35.9 5.6 Rate dNm/m 63.1 63.5 67.4 71.4 58.3 71.1 in MH-ML dNm 95.7 104.0107.9 110.5 94.7 123.5 Press Cure, 10 min at 180 C. Hardness Shore 72.072.0 73.0 78.0 73.0 75.0 A Tear Die lb/in 6.1 5.0 4.5 4.3 4.6 2.8 C  50%Psi 318.9 320.9 384.9 425.3 347.0 422.5 Modulus 100% Psi 515.7 582.1774.4 851.4 627.1 1151.1 Modulus 200% Psi 1240.7 1519.3 1895.5 2021.01501.7 — Modulus 300% Psi 2027.8 — — — — — Modulus Tensile Psi 2350.52337.3 2131.6 2227.9 2035.8 2127.5 Strength Elongation % 352.5 290.6222.6 219.8 260.5 155.6

The above described polymers may be used for vibration dampeningdevices, brake parts, hose compounds; extrusion profiles; powertransmission belts, thermoplastic vulcanizates, where tear resistancetear strength, tensile strength, elongation at break and other toughnesscriteria are critical and excess LCB may have a negative impact on thefinal product properties.

While the present invention has been described in considerable detailwith reference to certain preferred versions thereof, other versions arepossible. Also, different types of members and configurations of memberscan be formed in accordance with the invention, in a number of differentways that will be apparent to persons having ordinary skill in the art.Therefore, the spirit and scope of the appended claims should not belimited to the description of the preferred versions contained herein.

All documents cited herein are fully incorporated by reference for alljurisdictions in which such incorporation is permitted and to the extentthey are not inconsistent with this specification. All documents towhich priority is claimed are fully incorporated by reference for alljurisdictions in which such incorporation is permitted. Althoughdependent claims have single dependencies in accordance with U.S.practice, each of the features in any of the dependent claims can becombined with each of the features of one or more of the other dependentclaims dependent upon the same independent claim or claims.

1. A polymer product which comprises in combination: a) from 50 to 90mol % of ethylene derived units; b) from 0.1 to 2 mol % of VNB derivedunits; c) a balance of higher alpha olefin derived units; d) a branchingindex of greater than 0.7; and e) an optional amount of ENB derivedunits but less than the amount of VNB.
 2. A polymer according to claim 1which has an Mw/Mn<6 and/or an Mz/Mw<5.
 3. A polymer according to claim1 having a branching index greater than 0.9.
 4. A polymer according toclaim 2 which contains 50 mol % to 8 mol % of ethylene derived units,from 0.1 mol % to 0.5 mol % of vinyl norbornene derived units andpropylene derived units forms the balance.
 5. A polymer according toclaim 2 which has a Mooney viscosity of from 15ML to 100 MST.
 6. Apolymer according to claim 2 comprising 0.1 to 1 mol % of VNB derivedunits.
 7. A polymer according to claim 6 comprising 0.1 to 0.5 mol % ofVNB derived units.